1. Field of the Invention
The invention relates to a method for the chemical cleaning of cooled waveguides, in particular water-cooled waveguides of electric machines and apparatus, whose cooling cycle is maintained by a feed pump and has an ion exchanger in a closable bypass. If the method is to be used for cleaning differently cooled waveguides, these devices must, as a rule, be newly designed.
2. Description of the Prior Art
Methods are known for cleaning of water-cooled waveguides wherein the closed cooling cycle is opened and connected to a cleaning means. This intervention in the installation costs time and labor and a relatively long down time since access to the installation is required for a long time.
After connection of the cleaning means, which comprises essentially a cleaning tank and a cleaning agent pump as well as a condensation replenisher, the cooling water is drained from the cooling cycle of the wavegude, and then cleaning agent is filled in and circulated. Cleaning agents used are pickling solutions which contain e.g., mineral acid (sulfuric acid, hydrochloric acid, etc.) and sometimes additionally oxidants (potassium bichromate, ammonium peroxydisulfate, etc.).
After the pickling solution has become inactive, it is drained. If desired, additional pickling cycles follow. To protect the surface of the waveguides (roughening) and in order not to diminish the wall thickness of the waveguides too much, the pickling time must be kept as short as possible, so that often a compromise must be found between the cleaning result and the attack on the waveguide surface.
Another problem arising from this method is the disposal of the spent pickling solution.